Micro Capillary Pumped Loop for Electronic Cooling
289
The test condition in Fig. 22 was the weak heat dissipation at the condenser. That is, the
cooling water was not circulated at the condenser in order to investigate only the normal
operating characteristic of the micro CPL by phase change of the working fluid. In the case
of the heat pipe with the mechanism of vapor-liquid phase change, the heat pipe shows
isothermal characteristics which transfer a lot of heat in small temperature difference
between the evaporator and the condenser. Therefore, the normal operating state could be
confirmed by measuring the temperature difference between the evaporator and the
condenser when small power is input to the evaporator. In Fig. 22, the micro CPL with
working fluid shows lower thermal resistance than the micro CPL without working fluid in
both cases of total length being 50 mm and 70 mm. This means that the fabricated micro
CPL in the present study operates normally through the operating mechanism of vapor-
liquid phase change. In the case of the total length of 50 mm, the micro CPL with working
fluid shows lower thermal resistance about half of that of the micro CPL without working
fluid. In the case of the total length of 70 mm, the micro CPL with working fluid shows
lower thermal resistance about a third of that of the micro CPL without working fluid.
This means that although the total length is increased from 50 mm to 70 mm, the micro
CPL with working fluid operates normally by vapor-liquid phase change. However, the
thermal resistance of the micro CPL increased when the total length was changed from 50
mm to 70 mm.

012345
0
5
10
15
20
25



012345678
4
8
12
16
20
24Thermal Resistance (
o
C/W)
Input Power (W)
Micro CPL of 50mm length
Micro CPL of 70mm length

Fig. 23. Heat transfer rate according to increasing input power
4.4 Flow visualization of the micro CPL
Fig. 24 shows some images obtained by the visual inspection. They were captured on
arbitrary time while the micro CPL is operating. Figs. 24(b), (c), and (d) show the fluid flow
patterns in the path of the condenser. The fluid flow patterns in the micro CPL were very
active during the time the results of Fig. 24 are being obtained. Although any change in the
evaporator and the vapor line filled with vapor could not be seen with the naked eye, we Fig. 24. Flow patterns at the condenser: (a) top view of the condenser; (b) (c) plug flow
patterns on low or middle heat flux (1–6 W), respectively; (d) annular flow pattern on high
heat flux (over 7 W)


composed of only two layers.

Fig. 25. FPMHP considering commercialization

Heat Analysis and Thermodynamic Effects
292 Fig. 26. Micro CPL considering commercialization
6. Conclusions
The characteristics, design, fabrication and thermal performance of MHPs and micro CPLs
were investigated.
Firstly, MHPs with polygonal cross section applicable to electronic units with thin structure
were manufactured and tested. The high productivity and simple manufacturing process
were also considered for future applications. The manufactured MHP showed good
isothermal property over the total length, and the temperature difference between the
evaporator and the condenser was about 4–6 °C. The inclination angle had a slight effect on
the thermal performance, and the thermal characteristic was stable from the top heating
mode to the bottom heating mode. The effect of the total pipe length on the thermal
performance of the triangular MHP was dominant. In the case of the triangular MHP, the
overall heat transfer coefficient was enhanced by about 92% when the total length was
decreased from 100 mm to 50 mm for 3 W of thermal load. The heat transfer limit of the
triangular MHP was 7 W, which is 1.6 times larger than the 4.5 W heat transfer limit of the
rectangular MHP. The heat transfer limit, which was the function of the operating
temperature, increased when the operating temperature was increased. The maximum heat
transfer limit of the triangular MHP was 10 W for the operating temperature of 90 °C. In the
present study, the heat transfer limit was 1.7–2.1 times larger than that of Moon (Moon et al.,

ASME 1999, Vol. 3, 1999, pp.53-60
B. R. Babin, et al., "Steady-State Modeling and Testing of a Micro Heat Pipe,"
ASME J. of Heat
Transfer
, Vol. 112, No. 3, August, pp. 595~601, 1990
D. Wu, et al., "Investigation of the Transient Characteristics of a Micro Heat Pipe,"
AIAA J.
Thermophysics Heat Transfer, 5(2), April, pp. 129~134, 1991
F. M. Gerner, "Flow Limitation in Micro Heat Pipes,"
AFSOR Final Report, No. F49620-88-6-
0053, Wright-Patterson, AFB, Dayton, OH, 1989
G. P. Peterson, “An Introduction to Heat Pipes: Modeling, Testing and Applications,”
Wiley:
New York, NY, 1994
H. Xie, et al., “The Use of Heat Pipes in the Cooling of Portables with High Power
Packages,”
Thermacore Co., Technical Note
J. Kirshberg, et al., “Cooling Effect of a MEMS Based Micro Capillary Pumped Loop for
Chip-Level Temperature Control,”
ASME 2000, MEMS Vol.2, 2000, pp.143-150
J. S. Suh, et al., “Friction in Micro-Channel Flows of a Liquid and Vapor in Trapezoidal and
Sinusoidal Grooves,”
Int. J. of Heat & Mass Transfer, Vol. 44, 2001, pp.3103-3109
K. S. Kim, S. H. Moon, C. G. Choi, “Cooling Characteristics of Miniature Heat Pipes with
Woven-Wired Wick,”
11th Int. Heat Pipe Conf., Japan, Sep. 1999
L. Meyer, et al., “A Silicon-Carbide Micro-Capillary Pumped Loop for Cooling High Power
Devices,
” 19th IEEE Semi-Therm Symp., 2003, pp.364-368
M. C. Zaghdoudi, et al., “Theoretical Investigation of Micro Heat Pipes Performance,”

, 1984.
14
The Investigation of Influence
Polyisobutilene Additions to Kerosene
at the Efficiency of Combustion
V.D. Gaponov
1
, V.K. Chvanov
1
, I.Y. Fatuev
1
, I.N. Borovik
2
, A.G. Vorobiev
2
,
A.A. Kozlov
2
, I.A. Lepeshinsky
2
, Istomin E.A.
2
and Reshetnikov V.A.
2

1
OAO “NPO Energomash”
2
Moscow Aviation institute (State Technical University)
Russia

thermodynamic value mass flow complex β
t
.

Heat Analysis and Thermodynamic Effects

296
2. Composition and structure of test stand
Experimental investigation of influence 0.05% polyisobutilene additions to kerosene was
fulfilled at the test-bad № 72-2 department 202 MAI for fire tests liquid rocket engines of
small thrust (LRE STh) at ecological clean propellants [2]. Hydraulically pipe line of
kerosene is selection pipes from stainless steel of variable diameter (4-16mm) total length
8.12m. Pipe line connects kerosene tank with investigated mixing head and consists control
valve, filters (net 7 and 70 micro meters), sensors of mass flow, pressure and temperature
(Fig. 1). Fig. 1. Kerosene feeding system.
Take into account fire danger of mixture drops of kerosene with oxygen, for the obtaining
characteristics of pulverization the special drops-trap was designed and fabricated. Scheme
of this drops-trap is showed at Fig. 2.
The Investigation of Influence Polyisobutilene
Additions to Kerosene at the Efficiency of Combustion

297

Fig. 2. Scheme of drops-trap.
Drops-trap consists from tube diameter 400mm, upper top with mounted kerosene pipe
with injector (or mixing head), two diameterally opposite orifices for registration quality of
pulverization, low lid with branch pipe drain of kerosene and system of forced extraction

8- digital camera;
9 – computer.
Fig. 5. Structure scheme of а base distanced laser measurer:
Bloc of transferred lenses 3 contains field diaphragm and, some times, collimator forming
probe-rays and sizes of measured volume. Bloc of entranced optics contains Furie-linses,
having focus-distance 50-100 cm and light diameter 10-20 cm.
Focus distance of lenses, entranced in collimator, is changed from 10mm till 20cm.Because of
small sizes of parts(2-10micron)and big distances(till 2m) diameter most information part of
spatial specter, in which about 90% energy dispersed radiation is consisted , is obtained
more 20 cm.
Therefore, in order to fix this specter directly at photo-matrix, it is necessary to fabricate it’s
specially, but it go to big expenditures. In order to fix this spatial specter by series digital
camera 8, in frequency plate bloc of entrance optics was mounted light dispersion screen 5,
which visualizes the spatial specter. In order don’t spoil matrix of camera 8 by direct laser
ray, behind screen 5 sometimes expediently to place mask 6, absorbed direct laser radiation.
Sometimes, in order to decrease light-dispersion between elements of screen 5, mask is
placed before screen. For decrease influence of background light before lenses of camera 8
may to place interference light-filter 7. For two lengths wave of laser radiation light-filter
may by changed or special to fabricate. The spatial specter, fixed by digital camera 8, goes in
computer 9, where with help of special software the sizes and concentrations parts of

Heat Analysis and Thermodynamic Effects

300
aerosol are calculated. Control of laser radiations is realized across computer 9 (for increase
of the mobility notebook is used).
Transferred bloc of measurer contains half-conductor laser 1(Fig. 6) (length wave 650 nm,
type of laser KLM-650/20) and field diaphragm 2mm,wich decrease diameter of laser ray,
tested measured volume with drops of pulwerizated.
Light, distributed in direct direction 4 and under small angles, put at Furie-linse 5, in focal

For the treatment obtained drops and calculation parameters of dispersion of aerosol cloud
the program is used, developed in MAI at department 201 and realized at the base packet
MATLAB (Fig. 7). Fig. 7. Interface program calculation of parameters aerosol dispersion.
Laser device is montage at two controlled by altitude tables, placed at different sides from
drops-trap (Fig. 8). Axes of scanner ray go in orifices of drops-trap.
In order to separate factor influence of molecules polyisobutilene at the pulverization, the
cone of pulverization of single swirl injector with geometrical characteristic
()
2
3.2
nozzle in
ARr nr== and nozzle diameter 0.8 mm was analyzed. Distance from nozzle cut
off till surface of scanning consists 60 mm.
Estimation of quality of dispersion for common surface area defined by Sauter's diameter
parameter. Diameter Sauter is diameter of thermometric drop which has volume\surface area
coefficient equal middle volume\surface area coefficient calculated of whole drops in volume.

Heat Analysis and Thermodynamic Effects

302

Fig. 8. Laser device mount in the fire stand.
Results investigation pulverization of centrifugal injector are presented in Table 1.

Presence of
addition
Mass

4.2 12.0 4.6 3.55 1.05 8.4 3.48
With
addition
5.38 14.8 6.44 5.44 1.0 9.36 2.94
Table 1.
Analysis of obtained results lets to approve, that 0.05% addition in polyisobutilene in
kerosene to improve quality of pulverization ( at equal mass flow of kerosene), about this
show decrease of diameter Sauter approximately in 1.5 times. We may white better quality
of pulverization during fire tests, because by antypressure in combustion chamber quality of
pulverization will be better [5].
It is well known, that median diameter of drops during the pulverization of liquid by swirl
injector is obeying the dependence [6]:
()
0.6 0.1 0.7
47.8 Re
mc
dd A=∏
,
2
LLLc
d
ηρσ
∏=
,
The Investigation of Influence Polyisobutilene
Additions to Kerosene at the Efficiency of Combustion

303
Re
LecL

4. Investigation influence of polyisobutilene addition to kerosene at the
hydraulic resistance of pipe line
For normal kerosene the mass flow rate is 12 gr/sec for feed pressure 10 atm in filter/no
filter cases. For kerosene with polyisobutilene addition the mass flow is 4 gr/sec if filter
exist on the pipe line and 16 gr/sec if filter absent on the pipe line.
Result (Fig. 9) show that 7 micron filter increase hydraulic loss even if length of pipe line
is not big. If case using this kind of filters in LRE pipe lines the hydraulic loss will
be sizeable in the cooling jacket of combustion chamber. Without 7 micron filter the
hydraulic loss of pipe line increase. The influence of 70 micron filter on hydraulic loss not
defined. Fig. 9. Feeding pressure/mass flow rate dependency.

Heat Analysis and Thermodynamic Effects

304
5. Design of LRE of small thrust for fire tests
Combustion efficiency of propellant in the combustion chamber depends not only from
quality pulverization of injector. It depends and from a lot of additional factors: mass flow
ratio, number of injectors and scheme its placement at mixing head, combustion chamber
pressure, system of inner cooling and others. It is clear, that for separation influence of
addition to kerosene it is necessary to fulfill two fire tests at the same engine and the same
regime parameters.
For realization fire tests with the use addition of polyisobutilene to kerosene in MAI was
developed engine MAI-200-7ОК at propellant gaseous oxygen and kerosene (see Fig. 10 -
Fig. 12) [3, 8, 9].
A small number of experiments and the difference in the initial parameters of the
experiments cannot define exact dependency of polyisobutilene additions on the quality of
the spray component.

Fig. 12. Photography of mixing head.Heat Analysis and Thermodynamic Effects

306

Fig. 13. Plate of fuel. Red arrow - inlet of fluid. Fig. 14. Plate of oxidizer. Red arrow - inlet of gas.
Mixing head connect with combustion chamber across compressed cupper ring. The
fighting of bolts at flange is fulfilled with help of dynamometer key, in order to except
unevenness compressed forces. Before fire tests the compressing of engine is fulfilled:
combustion chamber in critical area is condensed by flange with central rubber cone.
Flanges of head and condensed element are jammed by studs. During compressing the
compression of connection chamber with mixing head and placement of candle are
examined.
The Investigation of Influence Polyisobutilene
Additions to Kerosene at the Efficiency of Combustion

307
6. Investigation influence of polyisobutilene addition to kerosene at the
combustion efficiency kerosene - oxygen propellant
Fire tests were fulfilled at the combustion chamber with short nozzle part (Fig. 15). That
methodic of test lets to exam workability of own combustion chamber during long works
without the use high expenditure vacuum equipment.

Entrance F
Candle of
ignition
Sensor of
pressure

Heat Analysis and Thermodynamic Effects

308
Tests of engine are fulfilled in two stage:
• tuned tests (duration < 0.5 sec);
• pass tests (duration < 5 sec) (Fig. 16);.
Results of pass tests are presented in Table 2.

Kerosene \
Parameter
о
m , gr/s
г
m , gr/s
m
k
к
p
, atm
Э
β
, sec
Т
βFig. 18.
Mass flow rate.

Heat Analysis and Thermodynamic Effects

310

Fig. 19.
Mass flow complex (C*). Fig. 20. Efficiency of chamber pressure
p
k
ϕ
.
The Investigation of Influence Polyisobutilene
Additions to Kerosene at the Efficiency of Combustion

311
The result show that addition polyisobutilene to kerosene (0.05%) don’t influence at
combustion efficiency
p
k
ϕ
of propellant in limit mistake of measurements.

jeksperimental'nyh issledovanij. Tehnicheskij otchet po Kontraktu № 30610 –
02020/ 980 – 09 – 187 mezhdu MAI i OAO NPO «Jenergomash» im. akademika
V.P. Glushko (2 jetap). Moskva, 2009.
[5] Kozlov A.A., Borovik I.N., Vorob'ev A.G. Tehnicheskij otchet po Kontraktu № 40440 –
02020/ 980 – 10 – 190 mezhdu MAI i OAO NPO «Jenergomash» im. akademika
V.P. Glushko (3 jetap). Moskva, 2010.
[6] Kudrjavcev V.M. Osnovy teorii i rascheta ZhRD. Moskva, «Vysshaja shkola», 1975.

Heat Analysis and Thermodynamic Effects

312
[7] Chvanov V.K., Fatuev I. Ju., Gaponov V.D., Sternin L. . Uluchshenie harakteristik raket-
nositelej pri dobavlenii k toplivu vysokomolekuljarnyh prisadok. Dvigatel', № 6
(42), 2005.
15
Synthesis of Novel Materials by
Laser Rapid Solidification
E. J. Liang, J. Zhang and M. J. Chao
Zhengzhou University
China
1. Introduction

High power lasers have been widely used in industry as well as in laboratory for materials
surface heat treatment, cladding, welding, cutting, thin film deposition by laser ablation and
so on (Bogue, 2010; Chao & Liang, 2004; Wang et al., 2008; Kruusing, 2004), but they are
seldom used in the synthesis of pure bulk materials. In recent years, we explored the
synthesis of pure bulk materials with a high power CO
2
laser (Liang et al., 2007; 2007; 2008;
2009; Zhang et al., 2010). It is shown that a variety of materials can be successfully